1. Field of the Invention
This invention relates to method and apparatus for moving a battery into and out of position on a mobile machine and more particularly to method and apparatus for lifting a battery holder or box containing an electrical battery from an initial position on the ground to an elevated position on a machine for transporting the battery for use in powering electrical vehicles and equipment in an underground mine.
2. Description of the Prior Art
In underground mining operations it is conventional practice to supply electrically driven vehicles and electrically operated equipment with electrical power supplied from storage batteries. The batteries in some instances may be stationarily positioned at a fixed power station or mounted on mobile equipment for providing electrical power to the vehicle that transports the battery. After a period of use a spent battery must be replaced on the vehicle or at the power station with a charged battery. This requires that the spent battery and the charged battery be moved into and out of position at the place of operation.
Battery changers and exchanging devices are well known for use in transporting a battery from one location to another in a mine. An example of a vehicle battery changer is disclosed in U.S. Pat. No. 3,799,063 and includes a mobile vehicle having a low profile adaptable for use in low overhead subterranean locations, such as mine shafts. The vehicle is propelled by electric motors that are powered by electric storage batteries containing a substantial number of cells and are a substantial size and weight. The batteries are positioned in cases or boxes which are supported in compartments built into the frame of the vehicle. The batteries contained in the cases are electrically connected to the vehicle drive and control mechanisms. Lift arms are pivotally mounted to the vehicle frame and releasably attached at their free ends to the battery case. The lift arms are pivotal laterally and outwardly from the upright walls of the vehicle. The batteries on the vehicle must be replaced when the electrical charge falls below the minimum required to supply the necessary power to the vehicle. The ends of the lift arms are connected to the battery cases and the piston cylinder assemblies extending between the vehicle frame and the pivot arms are actuated to pivot the arms outwardly from the upright walls to lift the battery cases out of the compartments and lower the batteries onto the ground where the lift arms are disengaged. The spent batteries are then replaced with charged batteries which are connected to the lift arms. The lift arms are raised by the piston cylinder assemblies from the outboard position to the inboard position and then lowered into place in the battery compartment.
Where the lift arms are required to pivot laterally and outwardly from the upright walls of the vehicle, ample space must be provided between the vehicle and the side walls of the mine shaft for the batteries to be raised and lowered into and out of position in the battery compartment. In addition, substantial overhead clearance must be available to permit the battery to be raised to an elevation above the vehicle for lowering the battery into position in the battery compartment.
U.S. Pat. No. 4,397,365 discloses a front end loader powered by an electrical traction motor system. The electrical power is supplied from a storage battery that is carried by a lifting frame swingably connected to the chassis frame of the vehicle. After a period of time of operation of the front end loader, a spent battery must be exchanged for a charged battery. During the battery exchange operation the power is switched over to a low tension voltage battery on the vehicle. The high voltage battery is then disconnected from the electrically operated equipment on the vehicle. The vehicle is moved into position adjacent a pallet for receiving the spent battery. The pallet is positioned on the ground. To position the spent battery on the pallet, the lifting frame is elevated and guided into openings on the pallet to receive the battery box. The lifting frame is lowered to in turn lower the battery box on the pallet. The lifting frame passes through the openings in the pallet so that the battery box is transferred from the lifting frame to the pallet. The vehicle is then moved to another location where a charged battery is positioned on a pallet. The lifting frame is moved into a position to engage the charged battery on the second pallet. The vehicle is then backed away from the second pallet to transfer the charged battery from the pallet to the lifting frame. Thereafter, the battery is elevated by the lifting frame to complete the electrical connection of the charged battery to the operating equipment on the vehicle. The low voltage battery is then disconnected. This operation requires a substantial amount of space for maneuvering a spent battery into position on a pallet and then moving the vehicle to another pallet to pick up a charged battery, followed by transfer of the charged battery onto the vehicle. The lifting frame must be elevated above the vehicle frame in order to complete the connection of the replacement battery to the operating equipment. Therefore, substantial overhead clearance is required to change a battery.
U.S. Pat. No. 3,834,563 discloses a battery carrier by which a battery is raised from a position on the ground a minimum vertical amount and then by pivotal movement of arm assemblies is moved in a substantially greater transverse motion into a battery compartment of an electrically powered mine car. The arm assemblies are actuated by hydraulic piston cylinder assemblies to move the battery from an initial position removed from the vehicle, such as on the ground, upwardly to a vertical height a sufficient distance to clear a threshold bar of the battery compartment. The pivot arm assemblies are then moved to transfer the battery in an arcuate path into the battery compartment. Initially the battery is positioned laterally of the side wall of the vehicle so that in a confined space, such as a mine shaft, sufficient space must be available between the side wall of the mine shaft and the side wall of the battery compartment to allow for the upward and laterally swinging movement of the pivot arms. A spent battery is removed from the vehicle through the same range of movement.
U.S. Pat. No. 3,782,750 discloses a battery truck containing a box in which a large storage battery is positioned. The box completely surrounds the battery. The floor and side walls of the box are supported by a carriage that is movable by action of lever and eccentric cams to raise and lower the battery box on the truck frame. When in use, the battery is positioned in the box which rests on a fixed surface, such as the surface of a battery compartment on a vehicle where the battery is used. Once the battery is spent and is to be replaced with a charged battery, the carriage is lowered so that the battery box is raised above the supporting surface to permit the truck to be moved. When the truck is in the desired location, the battery box is then immobilized as the carriage is raised to lower the bottom of the box onto a supporting surface.
It is also known to exchange spent batteries on electrically powered equipment by moving a battery transport mechanism into position adjacent the spent battery on a vehicle. The support structure is moved laterally into underlying engagement with the spent battery to lift the spent battery from the electrically powered vehicle and transfer the battery to the adjacently positioned transport mechanism. An example of a battery handling device of this type is disclosed in U.S. Pat. No. 4,808,058.
U.S. Pat. No. 3,327,875 also discloses apparatus movable into position adjacent an electrically powered vehicle for transferring a battery from the vehicle to an adjacent carriage. This permits the battery to be removed from the vehicle and a replacement battery installed.
U.S. Pat. Nos. 4,299,526 and 4,342,533 are further examples of battery changing apparatus that include transfer mechanisms for lifting vertically and horizontally batteries into and out of position on the support surface of an electrically powered vehicle. Each of these devices require substantial clearance around the battery and the electrically operated equipment to facilitate the movement of the battery transfer device into and out of position to exchange batteries on the vehicle. These devices are not suitable for use in confined spaces, such as mine shafts, where minimal area is available for maneuvering of the electrically powered vehicle or the mechanism for transferring the batteries on the vehicle.
Therefore, there is need to provide battery changing apparatus that is suitable for use in an underground mine where limited lateral and overhead clearance is available for movement of a battery box or battery holder into and out of position on a vehicle that transports the battery throughout the mine. While the prior art devices disclose various mechanisms for handling batteries on a vehicle and particularly an electrically powered vehicle used in underground mining, there is need for battery changing apparatus that is operable to pick up a battery from the ground and move it to a secure operating position that does not require lateral or vertical movement of the lifting apparatus beyond the operating position. The range of movement of the battery changer must allow exchange of batteries on a vehicle in areas having low overhead clearance. Where the side walls of the vehicle are positioned closely adjacent to the side walls of a mine shaft the battery change must be accomplished without requiring lateral movement of the battery.